It says that not only death, but resurrection both came by man. I know that eternal life is life void of death. So where does resurrection come into play as it came by man where as the God of all grace is eternal life void of death with no resurrection needed?

Shawn,

Grace, and Mercy, and Peace unto you,
from God, our Father, and our Lord JC.

Let's look at it with 1Cor 15:20-22 content:
But now is Christ risen from the dead, [and] become the firstfruits of them that slept. For since by man [came] death, by man [came] also the resurrection of the dead. For as in Adam all die, even so in Christ shall all be made alive.

We have 2 statements sandwiched between 2 questions.
Q1 - is Christ risen from the dead?
S1 - death & resurrection both by man
S2 - as in Adam all die (a bad ending)
Q2 - in Christ shall all be made alive?

Let's first look at the statements in midst:
S1: Death is by Adam1, Resurrection by Adam2;
Both = "grave" (law) subject. Grace & Turth isn't.
Eg: Mt 22:32; Mk 12:27; Lk 20:38 thrice clarify this:
he's not God of the dead: law, but of the living: grace.
So then there are no dead to resurrect in God of living.
Eg: "let the dead bury their dead" notably occurs twice,
for both sides of 2D's Dead1/Dead2 = "twice dead" (Jude).
So then "believe [it] not" also occurs twice: Mt 24:23,26,
for both sides of law/law = death/resurrection believers.
Think about it: where does better resurrection land you?
In heaven? No. It lands you back on earth for a do over.
So then Hebrews 6 says to LEAVE resurrection of the dead.
It's a pre-requisite for going on unto perfection above.
It's similar to first put off old man to put on new man,
for if mingle such: new wine in old bottle = Judas burst.
So, just as you leave Dead1 to go on to Dead2 of 2D mode,
so also leave both Dead1/Dead2 of 2D to go on unto Alive.

S2: as in Adam all die = as in Adam1 AND as in Adam2.
Paul clarifies it in 2Tim 3's last days also peril-us.
So then we have reasons for leaving 2D God for 3D God.
But if not willing to leave 2D, then you cannot go on.
Eg: Heb 7:23 "not suffered to continue by reason of death.

Q1: is Christ risen from the dead? Answer: Yes.
Christ is neither Adam1 nor Adam2, but above both dead.
So Christ is risen, is different word than resurrected.
Eg: 15:13,14 resurrection = anastasis; risen = egeiro.
Christ did the will of God before the cross, not at it.
Heb 10 says do will of God precedes receive the promise.
Christ refused "mingled" drink from both sides of cross.

Q2: in Christ shall all be made alive? Optional answer:
if yes, then also you & all KofG within you
if no, then not you either: Romans 2:1-11.

Lots of other details, but that's my brief version.

The grace of our Lord Jesus Christ [be] with you all. Amen.

Thank you for your reply. So then those that don't go on unto perfection are resurrected, for a (do over) via a (better resurrection?)

Shawn,

Grace, and Mercy, and Peace unto you,
from God, our Father, and our Lord JC.

To grasp things said in 1Cor 15 it helps to first look at 1Cor's big picture, via the begin and the theme and the end.

The <[end note]> says this:
<[The first [epistle] to the Corinthians was written from Philippi by Stephanas and Fortunatus and Achaicus and Timotheus]>. So there were four who penned what Paul orated at Philippi; And Paul only & always personally hand signs the very end of his epistles with his "token" of grace (allegorically the ticket to higher heaven), but notably it's the grace of "our Lord Jesus Christ" (not their Lord CJ, nor the Lord JC). See these two web pages about such things:

The End: http://sabelle.com/godshew/RevelatorySermons13.htm

<[End Notes]>: http://sabelle.com/godshew//PaulsEpistles.html

Both in the begin and end of 1Cor Paul mentions both CJ and JC; But in the begin (1Cor1) he notes he's an apostle of JC speaking to CJ people (carnal, childish Christians) who still have divisions among them. So notice his mention of two Lords: theirs and ours (aka theirs = CJ, but ours = JC). Also at the end of 1Cor Paul says two JC and CJ things, lastly expressing his love to CJ people, but as a JC person. I find it odd, even ignorant, that no preachers nor teachers of any churches get this, or ever teach on it; Indicating they don't (yet) know there's a difference. So I made several web pages about it, to help people notice the difference between CJ and JC; For CJ is the reverse, which contains the curse:

CJ isn't JC: http://sabelle.com/godshew/ChristJesus

Which is witch: http://sabelle.com/godshew/GodShew5.htm

Mirrorly Reversed: http://sabelle.com/godshew//SAQs.htm

So then, 1Cor 15 is trying to allegorically explain (to carnal childish people) the difference between several things: natural/spiritual, aka Adam1/Adam2, which are as different as terrestrial/celestial bodies, and thereby as different as mortal/immortal, aka soul/spirit; Which in Hebrews 4:12 firstly gets divided asunder by the word of God, aka by grace which is sharper than any twoedged sword (aka smarter than law/law = loser/loser or even law/grace = still division, not peace, if divided left/right instead of under/above). So let's notice in 1Cor 15 that Adam1/Adam2 = Under/Above (not Left/Right).

Also, for those who can receive it,
Christ is neither of Adam1/Adam2,
and because "as in Adam all die";
For terms like
"all die",
"all dead",
"all perish"
are law terms, and
the result is extinction, not salvation.

So, if we stay in 2D mode, then it's Dead1/Dead2 choice.
For even better resurrection is still a "grave" subject.
So Mt 22:32; Mk 12:27; Lk 20:38 thrice notes, about God:
He is not the God of the dead, aka Law;
He is the God of the living, aka Grace.
If thinking other-wise, it's ye "greatly err".

Try and digest that, about this/that.
For God is not a man that he should lie (law),
neither son of man that he should repent (change).
God is not the author of confusion, but of peace.
Peace with God is notably "through Jesus Christ";
And reconciled is then "through Christ God-ward".

So then, plural God is not (yet) "God is one"; And
God is one isn't one of twain, but one above twain.
Pure grace isn't grace of law/grace, but pure grace.
Pure grace has no twain, nor any mention of law at all.
So the end to endure unto has no mention of law = death.

The grace of our Lord Jesus Christ [be] with you all. Amen.